EDF characterization: identifying the origin of industrial corrosion

Corrosion observed on a part, assembly, or coating intended for the energy sector can compromise compliance, service life, and operational safety. Our approach to EDF Characterization aims to determine the origin of the corrosion in a factual way, based on surface observations, chemical analysis, and targeted tests. The goal is to distinguish pitting, galvanic, crevice, or general corrosion, identify any oxidizing agents, deposits, or contamination, and link the results to the material, manufacturing process, or exposure environment.

The assessment may include fractographic analysis to classify a brittle, ductile, or fatigue fracture, as well as observation of the fracture surface to highlight the contribution of corrosion. Comparisons between sound and failed areas are carried out through microstructure and hardness analysis. Observations using optical microscopy and SEM-EDX make it possible to examine cracks, irregularities, wear, localized attack, and corrosion products. The composition of the metal part can also be verified by ICP and elemental analysis to confirm the grade and compliance with specifications.

To anticipate corrosion phenomena before industrialization, the laboratory carries out electrochemical tests adapted to metallic materials and protective coatings. Measurements of open-circuit potential (OCV), corrosion rate (LSV), electrochemical impedance (EIS), and galvanic coupling make it possible to assess a material’s sensitivity to its environment, detect coating defects, and study the uniformity of protective layers. Salt spray and accelerated aging tests complete the performance assessment.

The assessment relies on a set of complementary technical resources: FEG-SEM, SEM-EDX, FEG-SEM-EDX, optical microscope, ICP-AES, XPS, XRD, AFM, roughness meter, durometer, potentiostat, elemental analysis C/S, N/O, H, and salt spray tests. This combination makes it possible to observe surface morphology, identify the composition of deposits and corrosion products, measure layer thickness or uniformity, assess the metallurgical condition, and study the electrochemical behavior of the material/coating/environment system.

The laboratory supports manufacturers from failure investigation through to validation of corrosion resistance before industrialization. The analysis combine metallographic observations, surface characterization, semi-quantitative identification of corrosion products, and electrochemical testing. This approach makes it possible to understand an observed defect, verify the uniformity of a surface treatment, measure coating thickness loss, and assess how a part performs in simulated environments. For related issues, it is also possible to explore the characterization of a deposit or contamination or investigate a case of premature corrosion on new piping.

For coated or treated parts, surface analysis are used to confirm the chemical nature of the layers, verify their uniformity, and detect delamination, coating failure, or adhesion defects. Investigations may use XPS, SEM-EDX, XRD, AFM, a roughness meter, and microsection analysis. This approach is particularly useful for linking corrosion to treatment heterogeneity, thickness loss, or surface contamination. Depending on the need, a material characterization study can complement the investigation to secure the interpretation.

Tests can be carried out in specific media to reproduce conditions close to actual use: seawater, extreme pH, the presence of inhibitors, or other aggressive environments. This comparative approach helps select a more robust grade, coating, paint, or surface treatment. It also makes it possible to rank several technical solutions before final qualification. In addition, certain material issues can be linked to a thermal characterization of materials by DSC when the overall behavior of the material needs to be consolidated.

Filab supports manufacturers with a problem-solving and technical validation approach. The laboratory steps in to quickly determine the corrosion origin, verify the compliance of a part or process, and secure material choices before integration into sensitive equipment. This ability to connect observations, analysis, and tests makes it possible to turn analytical results into operational decisions: confirm a grade, correct a surface treatment, qualify a coating, or adjust specifications. The laboratory also holds COFRAC accreditation for a publicly available scope and can support both R&D and production quality control.

After corrosion has been identified, it is important to preserve representative areas, document the conditions under which it appeared, provide the material and coating specifications, and then have the part analyzed according to a suitable investigation plan. The laboratory can then compare sound and degraded areas, identify corrosive agents, verify the compliance of the grade and surface treatment, and propose the additional tests needed to confirm the failure scenario. The approach can ultimately be extended through comparative testing to validate, anticipate, secure, and reliably support future industrial choices.